Having lost four of five, the Nets have a bunch of problems, but Deron Williams isn’t one of them.

The star guard, who has battled injuries all season, detoxified his body during the All-Star break last month and has been red hot since. He has lost weight, has more energy and spring, and says he finally can dunk again — even if he’s scared to try.

During the week when Williams was sidelined with inflammation in both ankles, he did a three-day juice cleanse that removed toxins from his body and gave him energy. He also received his third round of cortisone shots and PRP injections, and the results have been both successful and dramatic.

“My ankles don’t hurt,’’ said Williams, whose Nets play the Bobcats Wednesday night at Charlotte. “We finally got the injections in the right spot, and I feel a little bit better. I can actually go up and down stairs. I can run around with my kids. I can go to the playground with them. I don’t hurt every time I take a single step, so yeah, I feel a lot better.’’

In the seven games he has played since the All-Star break, Williams has averaged 21.7 points and 7.1 assists, shooting 45.5 percent from the 3-point arc and 89.5 percent from the free-throw line.

And perhaps most telling?

“I can dunk,’’ confirmed Williams, whose only attempt of the season came on Nov. 23 in Los Angeles, when he got emphatically rejected by Clippers forward Blake Griffin, fell and hurt his right wrist.

As for when he’ll try again in a game, he said, “I don’t know. I’m still nervous.’’

Williams, 28, dislikes discussing his health and hates talking about his weight.

“I’m glad you guys are concerned about me. It means a lot,’’ he said sarcastically.

USA Basketball president Jerry Colangelo had criticized Williams, saying he was overweight and “not in the best shape” when he aggravated his ankles during training camp for the London Olympics last summer. Williams insists he didn’t change his diet, but said he lost water weight and gained energy during his Blueprint juice cleanse.

“It was a three-day cleanse. It was when I got hurt and was sitting out. You can’t really do it in play. It’d be tough to do a cleanse in play. I knew I was taking a break, so I did a three-day cleanse,’’ Williams said. “It definitely helps your energy. It gets a lot of the bad toxins out of your system. That’s the main thing.’’

Nets interim coach P.J. Carlesimo said he could see the difference in Williams’ body.

“Right now, he’s really made a strong move addressing diet. I remember we were at a dinner the other night and he was drinking that some cleanse stuff or whatever the hell it was.

“He’s lost some weight, and the week off, close to a week off, I think it helped him,’’ said Carlesimo. “He looks good. He looks very good.”

*** The Nets are 3 1/2 back in the Atlantic Division, but aren’t focused on the division, Joe Johnson saying, “Right now we’re not worried about winning the division. We need to worry about winning a game.’’

*** Brooklyn has struggled mightily in the third quarter, averaging an NBA-worst 21.7 points per game without any answers as to why.

“I couldn’t explain it the other 100 times you asked me, and I can’t explain it now. … We just come out flat,’’ said Williams, who suggested to Carlesimo that the halftime speeches be scaled back to allow for more warmup time. “It didn’t work.”